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7th Grade Math / Lesson 2: Order of Operations

 ORDER OF OPERATIONS What will we be learning in this lesson? This lesson will review the order of operations with variable expressions.

 ORDER OF OPERATIONS Parenthesis   ( ),  [ ],  { } Exponents Multiplication/Division    from left to right Addition/Subtraction       from left to right   Which of the operations would be done first in each expression?     A.  20 - 4 * 5 + 1    B.  32   - 7    C.  (8-2)/3  + 5

 ORDER OF OPERATIONS Parenthesis   ( ),  [ ],  { } Exponents Multiplication/Division    from left to right Addition/Subtraction       from left to right   Which of the operations would be done first in each expression?   A.  20 - 4 * 5 + 1              Do the multiplication first   B.  32     - 7                        Do the exponent first   C.  (8-2)/3   + 5                 Do the subtraction in the numerator first

 ORDER OF OPERATIONS State the operation that is performed first Evaluate the expression (evaluate means "get an answer") 1.4 - 1 * 2 + 5                     2.6 * 3 - 1 + 9   3.5 - 2 + 7

 ORDER OF OPERATIONS State the operation that is performed first Evaluate the expression (evaluate means "get an answer")   4 - 1 * 2 + 5                      Multiplication first.      7 2.6 * 3 - 1 + 9                      Multiplication first.      26 3.5 - 2 + 7                           Subtraction first.        10

 ORDER OF OPERATIONS Evaluate the expressions using the following values. A = 4   B = 3   and   C = 2  4 - C * 2 + 5 2.A * B - 1 + 9 3.5 - 2 + B

 ORDER OF OPERATIONS Evaluate the expressions using the following values. A = 4   B = 3   and   C = 2  4 - C * 2 + 5         4 - 2 * 2 + 5    =    4 - 4 + 5 =     0 + 5 =   5 2.A * B - 1 + 9          4 * 3 - 1 + 9   =    12 - 1 + 9    =   11 + 9    =   20 3.5 - 2 + B                5 - 2 + 3   =   3 + 3   =    6

 ORDER OF OPERATIONS Put parenthesis into the following statement to make it true.        5 + 2 * 3 - 1 =  9

 ORDER OF OPERATIONS Put parenthesis into the following statement to make it true.        5 + 2 * 3 - 1 =  9 You need to just try putting parenthesis into different spots in the statement until you find the one that works. (5 + 2) * 3 - 1 7 * 3 - 1 21 - 1 20                Not this one.

 ORDER OF OPERATIONS Put parenthesis into the following statement to make it true.        5 + 2 * 3 - 1 =  9 Try a different spot. 5 + (2 * 3) - 1      5 + 6 - 1       11 - 1            10                Not this one.

 ORDER OF OPERATIONS Put parenthesis into the following statement to make it true. 1.5 + 2 * 3 - 1 =  9 Try a different spot. 5 + 2 * (3 - 1)      5 + 2 * 2       5 + 4           9                This one.                                  5 + 2 * (3 - 1) = 9   is the true statement.

 Can you evaluate an expression according to the order of operations? Be sure to go back to the lesson page to access your homework.